Rapid assessment of avoidable blindness in Iran

Area of Science:

• Ophthalmology
• Public Health
• Epidemiology

Background:

• Blindness and visual impairment (VI) pose significant public health challenges globally.
• Understanding the prevalence and causes of VI is crucial for targeted interventions.

Purpose of the Study:

• To determine the prevalence and causes of blindness and visual impairment (VI) in adults aged 50 years and older in the Varamin district, Iran.
• To identify the proportion of VI attributable to avoidable causes.

Main Methods:

• A cross-sectional, population-based survey using the Rapid Assessment of Avoidable Blindness (RAAB) methodology.
• Probability-proportionate-to-size cluster sampling of 3000 inhabitants aged ≥50 years, with a 94% response rate.
• Standardized visual acuity testing and ophthalmic examination to determine blindness, severe VI (SVI), and VI, and their primary causes.

Main Results:

• The standardized prevalence rates were 1.33% for blindness, 1.39% for SVI, and 6.91% for VI.
• Avoidable causes accounted for 56.1% of blindness, 65.0% of SVI, and 85.6% of VI.
• Cataract was the leading cause of blindness and SVI, while refractive error was the primary cause of VI.

Conclusions:

• A significant proportion of blindness and visual impairment in the Varamin district is due to avoidable causes.
• Cataract and refractive errors are the most prevalent treatable causes of VI in this population.
• Public health strategies should focus on addressing cataract and refractive errors to reduce the burden of VI.